Parts for your 2019 Holden Colorado-Ignition coils

2019 Holden Colorado ignition coils — are they used?

For the Australian and New Zealand–market 2019 Holden Colorado (RG series), ignition coils are not fitted and are not relevant. Technical sources make this clear: the Holden Colorado MY19 Owner’s Manual identifies the vehicle as powered by a 2.8‑litre Duramax turbo‑diesel and describes a glow plug indicator and pre‑heat process rather than any spark-ignition system. GM Global Service Information (SI) for the 2.8L Duramax (RPO LWN) specifies components such as the Glow Plug Control Module and common‑rail injection, with no reference to spark plugs or ignition coils. Diesel engine texts like Bosch Diesel‑Engine Management explain that diesels use compression ignition, so there’s no high‑voltage coil pack required to fire spark plugs.

Why no coils? A diesel ignites fuel by compressing air until it’s hot enough to burn the injected diesel—no spark needed. What the Colorado does have is a set of glow plugs to assist cold starts, controlled by the ECU via a Glow Plug Control Module. Once running, combustion is maintained by high compression and precise fuel injection, not a spark.

• What’s fitted instead of coils: glow plugs and a glow plug control module
• Core systems: high‑pressure common‑rail injectors, rail pressure control, engine management
• Driver hint: a glow plug lamp on the dash illuminates briefly before cold starts

For owners chasing rough running, hard starting, or misfire‑like symptoms on a 2019 Colorado, looking for ignition coils won’t help. Focus areas should be fuel quality and filtration, injector condition, glow plug operation, battery health (cold cranking amps matter on diesels), intake/boost leaks, and up‑to‑date ECU calibrations. Routine servicing—especially timely fuel filter changes—goes a long way to preventing issues that can feel like a “misfire” on a petrol but are fuel or compression related on a diesel.

If a parts search returns “ignition coils” for this model, it’s usually a catalogue mismatch with petrol variants from other markets or different model lines. For the 2019 Holden Colorado sold locally, there’s simply no ignition coil to replace.

• Does a 2019 Holden Colorado have ignition coils?
  No. The 2019 Colorado uses a 2.8L Duramax turbo‑diesel with compression ignition, so there are no spark plugs or ignition coils. Cold starts are supported by glow plugs, managed by a Glow Plug Control Module.
• What should be checked if it feels like a misfire on a diesel Colorado?
  Start with fuel quality, fuel filter condition, injector performance, glow plug operation, and battery health. Also check for intake or boost leaks and ensure ECU software is current. These areas commonly cause rough running on diesels.
• Are glow plugs a maintenance item on the 2019 Colorado?
  Glow plugs can wear over time, particularly with frequent cold starts. They’re not replaced on a fixed interval, but should be tested if cold starts are slow, there’s white smoke on start‑up, or the glow plug warning lamp behaves abnormally.